Is Your Workout Costing You Muscle, Bone, and Metabolism?

What if your workout is costing you muscle bone and metabolism? How easy it is to be swayed or confused by information if you’re not asking the right questions. During research for a master class recently I came across an article that prompted this post. My hope with this post is two fold. 1) You’ll understand what exercises support your muscle and fat optimization, and 2) that you’ll know how to ask the right questions of research. 

muscle bone and metabolism

Are You Getting the Whole Story?

When research is clear, but the use of it in articles is not always.

Where HIIT = high intensity interval training and RT = resistance training:

HIIT: burns fat and to a lesser extent builds muscle

RT: Builds muscle and burns fat after (acute) and at rest (long term)

Still, a recent article in popular and respected magazine suggested both …

  • If you decrease muscle mass, you burn fewer calories at rest.

I’ll inject a fact here: You spend a lot more time at rest than you do at exercise.

  • Went on to say, “cardio is the gold standard for weight loss.”

What? They contradicted themselves. Cardio alone will cause muscle wasting in older adults.

What I want to point out:

Correction: Cardio workouts are thought of as the gold standard for weight loss.

An individual at a lower weight burns fewer calories than a person at a higher weight, no matter what the body composition.

If you have less muscle mass, you burn even fewer calories during and after any exercise than a person of the same weight. You can’t cardio your way to a lean future without strength training.

And as a woman in midlife more susceptible to negative effects of stress, you can exhaust yourself before you ever get there.

In fact, doing lots of cardio will likely increase your cortisol. With cortisol imbalance fat storage is turned on and fat burning is turned off. Your body is performing a sort of self-preservation. When you’re under duress – whether self-imposed or not- your body will respond by protecting you and saving fat for your rainy day fund.

The Science Behind HIIT and RT Comparison

A study quoted in the article looked at effects of three kinds of exercise on young and older adults.

  • HIIT (High Intensity Interval Training)
  • RT (Resistance Training)
  • Combined (Performing the two together alternately)


HIIT>> the most influence on mitochondria protein synthesis in older adults

RT> most benefits increased muscle protein synthesis

Combined> significantly lesser results overall

If you want the full interpretation of this and other studies showing how to increase muscle over 50 with exercise and nutrition changes, you may want to watch this full master class replay. 

SPOILER ALERT: you may want to rethink your bootcamp-style workouts 80% of the time for optimal results)

“When HIIT and RT are combined adaptations (results) are lower.”

Namely, because the ability to sustain same intensity in either compared to when dedicated to the session is lower.

Are You Boosting or Losing Muscle Bone and Metabolism?

This study reinforces the need to distinguish the difference between being “exhausted” or “tired” at the end of a workout and truly reaching overload stimulus that improves fitness. You need to know the difference between moving fast exercise to exercise and reaching muscular fatigue and breathlessness during the strength or interval sessions.

If you don’t distinguish the difference, even if temporarily you may be under the spell of endorphins and feeling more fit, you could be on a path to fatigue and burnout.

Fitness feels good both while you’re doing it and after, short term and long term. True, there are those of us that are less inclined to exercise than others. Despite those feelings however, at the right exercise intensity for you, there should be no question you have more energy, not less.


  • Improves cardio fitness
  • Insulin sensitivity
  • Mitochondrial respiration
  • Fat-free mass


  • Improves FFM
  • Insulin sensitivity

Combined Training

Lesser results in any category

Age-Related changes (without intervention)

Decreased mitochondrial production:

  • Closely related to cardiovascular fitness
  • Related to insulin resistance
  • Related to obesity and type 2 diabetes

HIIT increased mitochondria respiration by 69%.

RT didn’t increase mitochondria significantly but upregulated a different set related to fat free mass and insulin sensitivity.

You may also want to read this article I wrote for Medium. 

muscle bone metabolism

It’s Not a Single Study or Isolated Benefit

Though there’s a smaller portion of research featuring women in and beyond menopause, it’s there. And facts about muscle bone and metabolism changes can be inferred from prior research. In other studies (along with this one) discussing muscle protein synthesis, RT and HIIT are again compared. Muscle Protein Synthesis (MPS) refers to your ability to use protein you eat for your muscle. Aging imposes a natural decline of MPS.

RT increases muscle protein synthesis significantly.

HIIT increases muscle protein synthesis to a lesser effect.

Studies show considerably different responses in older adults vs young adults.


If you’re doing the same workout as your daughter or mother one of you is not doing the most advantageous workout.

Even more important, if you are having the same post workout meal, one of you is not getting an on-target meal. Protein needs for older adults are suggested as high as double young adults to achieve the same result for MPS. (reviewed and cited in the replay also)

Muscle Bone and Metabolism Benefits for Women Over 50

Women in menopause do best with independent interval training and strength training workouts that focus on optimizing the specific training goal of each.

That’s as opposed to:

  1. Bootcamp-style co-mingled or combined workouts said to be more convenient and time effective


  1. “Cardio” type workouts of mid-range intensity. (I call this “no benefit zone.”)

Is there a place for those fast and efficient bootcamp style workouts? Yes, of course. If you have the time, and or if you absolutely know you need variety, once you’ve covered the bases and have a high quality strength training plan you perform regularly, and interval training sessions you do 1-2 times a week, apply using an 80/20 rule. If 80% of the time you do the most direct path to your goals, then sprinkle the other activities in.

Bootcamps, weight training, and interval training all should offer different types of load for muscles and for bones. That is, you want different movement, unique kinds of forces either in landing or on the muscle pull regularly for optimal results. Variety within each is a smart plan.

Key Reference:

Get a scale that measures! 

What’s Your Next Move?

If you’re seeking solutions to at home muscle (and bone) loss sparing and you want a program that respects you’ve been on the planet 50+ years with a mind that wants back-of-the-closet clothes and some joints that need to be a bit more careful, I’ve got you. The best next step is my 12-week STRONGER program. It’s open a few times a year. Learn more here. 

right fitness strategy over 50


Spread the love
Scroll to Top

Learn how to measure!

Prefer video format?
– Click/Tap Play Below –

how to measure
Play Video about how to measure
how to measure

Circumference outside of both arms, at the armpit

Right Triceps
Halfway btwn shoulder & elbow, arm extended.

Find the widest point of girth at the hips

Right Thigh
Standing with weight on both legs, measure halfway between knee cap and hip flexor

Right Calf
Standing with weight on both legs, find the largest point of calf.

how to measure woman outline

Measure from the rib cage just under breasts at bra line

At the belly button/umbilicus

Prefer video format?
– Click/Tap Play Below –

how to measure
Play Video about how to measure

Get Notified On The Next Session

Just enter your name & email to be notified on the next training…

Flipping Fifty Logo